title: Inhibition of soluble epoxide hydrolase after cardiac arrest/cardiopulmonary resuscitation induces a neuroprotective phenotype in activated microglia and improves neuronal survival.
abstract: Cardiac arrest (CA) causes hippocampal neuronal death that frequently leads to severe loss of memory function in survivors. No specific treatment is available to reduce neuronal death and improve functional outcome. The brain's inflammatory response to ischemia can exacerbate injury and provides a potential treatment target. We hypothesized that microglia are activated by CA and contribute to neuronal loss. We used a mouse model to determine whether pharmacologic inhibition of the proinflammatory microglial enzyme soluble epoxide hydrolase (sEH) after CA alters microglial activation and neuronal death. The sEH inhibitor 4-phenylchalcone oxide (4-PCO) was administered after successful cardiopulmonary resuscitation (CPR). The 4-PCO treatment significantly reduced neuronal death and improved memory function after CA/CPR. We found early activation of microglia and increased expression of inflammatory tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the hippocampus after CA/CPR, which was unchanged after 4-PCO treatment, while expression of antiinflammatory IL-10 increased significantly. We conclude that sEH inhibition after CA/CPR can alter the transcription profile in activated microglia to selectively induce antiinflammatory and neuroprotective IL-10 and reduce subsequent neuronal death. Switching microglial gene expression toward a neuroprotective phenotype is a promising new therapeutic approach for ischemic brain injury.
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, Oregon, USA.
authors.forename: Jianming
authors.initials: J
authors.lastname: Wang
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Fujiyoshi
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Kosaka
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Raybuck
authors.forename: K Matthew
authors.initials: KM
authors.lastname: Lattal
authors.forename: Mizuko
authors.initials: M
authors.lastname: Ikeda
authors.forename: Paco S
authors.initials: PS
authors.lastname: Herson
authors.forename: Ines P
authors.initials: IP
authors.lastname: Koerner
mesh_terms: D000818:Animals; D016887:Cardiopulmonary Resuscitation; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D047188:Chalcones / Q000008:administration & dosage / Q000627:therapeutic use; D004851:Epoxide Hydrolases / Q000037:antagonists & inhibitors*; D006323:Heart Arrest / Q000188:drug therapy* / Q000201:enzymology / Q000276:immunology / Q000473:pathology*; D016753:Interleukin-10 / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000096:biosynthesis; D008297:Male; D008568:Memory / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects / Q000276:immunology / Q000473:pathology*; D009474:Neurons / Q000187:drug effects / Q000276:immunology / Q000473:pathology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: C401834:4-phenylchalcone oxide; D047188:Chalcones; D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D004851:Epoxide Hydrolases